Drop-table.



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DROP TABLE. APrLIoA'rIN Hum AUG.1a.19oel.

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No. 848,353. PATENTED MAR. 26, 1907.

W. 'ELMBm JR.- DROP TABLE'.

APPLIUATION FILED AUG. 1B. 1906. I

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PATENTE-MAR. 2m 1907.

W. ELMER, JR.

DROP TABLE. APPLIUATION FILED AUG.18. 1906.

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No'. 848,353. -PATENTED'MARza 1907.

W. ELMBR, JR.

DROP TABLE;

APPLIGATION FILED AUG. is, 196e.

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APPLICATION FILED 4AUG. 18. 1906.

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WILLIAM ELMER, JR., OF ALT OONA, PENNSYLVANIA.

DROP-TABLE.

Specification of Letters Patent.

Patented March 26, 1907.

Application filed Angustvl, 1906. Serial No. 331,208.

To all whom, zr may concern.:

Be it lmown that I, I/VILLIAM ELMER, Jr., a citizen of the United Statesof America, residing in Altoona, in the county of Blair, in the btate ofIennsylvania, have invented a certain new and useful Improvement in Drop-` rIables, of which the following is a true and exact description,reference being had to the accompanying drawings, which form a partthereof.

My present invention is particularly designed for removing and replacingthe wheels of steam-locomotives, one or more pairs of wheels beingordinarily removed or replaced at a time, though my invention isgenerally applicable for removing objects from beneath heavy structuresand for putting objects under such structures whenever desirable.

In the form of my invention disclosed I have provided a well or pit inthe main working floor, over a portion of which the locomotive or otherheavy structure to be operated upon is located. A platform is arrangedin the portion of the pit beneath the structure to be operated upon, andmeans are provided for dropping this platform down into the pit andraising it again when desired. A similar platform or table is locatedina portion of the pit not covered by the structure to be operated upon.Means are provided for also dropping this platform down into the pit andfor raising it. The two platforms may advantageously be operated by asingle prime mover, and in the embodiment of my invention disclosed thisprime mover comprises an electric motor arranged to' simultaneouslyraise and lower the two platforms. A passage or runway is formed in thepit, which extends between the two platforms. In operation the structureto be operated upon is so located that the object to be removed may restupon one platform and when freed from the structure is dropped down intothe pit. The object is then moved through the runway or passage onto theother platform, by which it is raised to permit its removal from thepit. An analogous method of operation is followed when it is desired toreplace the object thus removed or generally to put any object in placeunder the structure.

'lhe various features of novelty which characterize my invention arepointed out' with particularity in the claims annexed to and forming apart of my specification.

For a better understanding of my invention and theadvantagesmpossessedby it reference may be had to the accompanyingdrawings and descriptive matter, in which I have illustrated anddescribed somewhat in detail one of the forms in which my invention maybe carried out.

Of the drawings, Figure 1 is a sectional elevation of my apparatus. Fig.2 is a plan view of the apparatus shown in Fig. 1. Fig. 3 is a sectionalelevation on the line 3 3 of Fig. 1, but on a larger scale than Fig. 1.Fig. 4 is a plan view on a larger scale than Fig. 2,

showing the arrangement of the operatingmotor` and its brakingmechanism. Fig. 5 is an elevation of the same, and Fig. 6 is a sectionon the line 6 6 of Fig. 5. Fig. 7 is a diagram of circuit connectionswhich may be employed.

In the drawings, 1 represents the floorlevel of a repair-shop or thelike in Vwhich my invention is employed. The upper edges of the side'walls 2 of an elongated vwell or pit are flush with the'floor 1. Theside walls 2 of the Vwell and the bottom walls 3 mayjadvantageously beformed of concrete. The elongated sides of the well are, in the formdisclosed, lined by metal plates 4, secured in place by anchor-bolts 5.

Adjacent each end of the well is located a platform or table 6,comprising beams 7, extending parallel to the length of the well, andbeams 3, extending transversely thereto. To the under side of eachplatform are se cured the upper ends of four vertical threaded rods 9.These rods pass through threaded nuts 10, suitably journaled in bearingsat the bottom of the well. The bearings proper for the nuts 10,' whichvmay be of any wellknown form and advantageously may be of the roller orball type, each comprises a bottom member 11, having a spherical underportion,'which is seated in the upper end of a tubular member 12. Theperiphery of each nut 10, 'which is circular in outline, is providedwith teeth lO/, 'which mesh with a corresponding worm-gear 13, carriedby one or the other of a pair of parallel shafts 14, which extend alongthe bottom of the well parallel to its length. As shown, each shaft 14carries t'woworm-gears 13, which coperate with two of the threaded posts9, connected to one platform, and two gears 13, which coperate with twoof the threaded posts secured to the other platform. The

gears 13, carried by one shaft and coperating 'with the threaded postsconnected to a single platform, are reversely threaded, as

are the coperating posts, so that while a rotation in one direction ofthe shaft 14 tends to similarly move all the posts9 engaged by its gearsthe end thrust exerted on each gear 13 1s balanced by the end thrustexerted on the other gear for the same table. As shown, a suitableframework 15 is provided at each end of the pit for securing in placethe supports 11 and for supporting bearings for the corresponding end ofthe shafts 14. Intermediate bearings for the shafts 14 may be carried byframe members 16. The supporting-frames 15 and 16 may be secured invplace by suitable anchor-bolts, as desired.

Vertical passages are formed in the bottom of the well proper to receivethe ends of the bolts or posts 9 when the latter are lowered. Thesepassages may be lined by tubular members 17. Tubular guides 18 for theposts may be secured to the lower ends of the 'members 12 by threadedconnections, as

shown. The guides 18 extend down in the tubular members 17.

The framework for supporting the bearings for the threaded posts of theright-hand platform, as viewed in Fig. 1, is extended to support a primemover, which in the form shown is an electric motor having itsarmature-shaft 19 geared to a counter-shaft 20, which is connected toone of the shafts 14 by a coupling 21. The shafts 14 are geared togetherby gears 22 of equal diameter. One end of the armature-shaft 19 carriesa brakedrum 23. Surrounding the brake-drum 23 is a braking membercomprising two substantially seinicircular metal ,members 24, havingears 25 at their upper ends,which are adjustably secured together by abolt 26. The lower ends of the members 24 are connected to links 27,pivotally connected together, and to a link 28 by a pin 27. The link 2.8is connected t0 a lever 29, pivoted at 30 to the framework supportingthe motor and carrying at its other end a counterweight 31. The members24 may be lined with segments 32 in the form of wooden blocks.

It will be understood that the counterweight 31 normally pulls the lever29 down about its pivotal point 30 with a force sufficiently great tocause the `brake-drum to be held stationary by the members 24. Adj acentthe counterweight 31 the lever 29 is secured to the yoke of a U-shapedarmature 33 by a link 33. Each leg of the armature 33 passes axiallyinto the corresponding one of a pair of coils 34 of the solenoid type.When suitable current is passed through the windings of solenoids 34,the armature is attracted and moves upward the end of the lever 29,connected to it. This releases the brakedrum from the braking members 24and alp lows the motor-armature shaft to be rotated.

Transverse deck or licor beams 35 extend across the top of the pit atintervals between the platforms. These support rails 36,

which extend parallel with the length of the well. Each platform carriesa pair of rails 37 in alinement with the rails 36. Track. irons or rails38, carried by the floor 1 at opposite ends of the pit, extend to theends of the rails 37. As shown in Figs. 1 and 2, the rails 38 at theright-hand end of the well extend over the motor and are supported bydeck-beams 35.

In the normal operation of the device the platforms are adjustedvertically, so that the rails 37 are at the same level with the rails 36and 38, and the rails 36, 37, and 38 then form rails 37 are never raisedabove the rails 36V and 38.

In the use of my invention to remove a pair of wheels from a locomotivethe locomotive is run onto the rails 38, 37, and 36 to bring the pair ofwheels to be removed over one of the platforms or drop-tables-as, forinstance, the left-hand one shown in Fig. 1. After the wheels aredisconnected from the locomotive structure the motor-brake is releasedand the motor set in operation to drop the platforms down in the wellfar enough to bring the upper surfaces of the rail-sections 37 in aplane with the upper surface of a pair of abutments 39, which may beformed of concrete and extend parallel to and one at each side of theshafts 14. The wheels are then moved from the platform on which theyhave been lowered to the other platform, after which the platforms areraised to the floorlevel. The wheels are then moved off the rails 37 onthat platform onto the rails 38. In replacing the wheels a reverseoperation is performed.

A single motor for operating both platforms may readily be employed,since the maximum load on each platform is ordinarily the same and oneplatform only is loaded at a time. The winding of the electromagneticbrake-releasing device may advantageously be in series with the motor,since such an arrangement insures that the brake is in the holdingposition except when the motor is operatively energized.

The circuit arrangements which may be employed for the motor andbrake-releasing device are shown in Fig. 7, where 40 and 41 representthe conductors supplying current, 42 represents the field-winding of themotor, 43 the armature, and 44 the windings of the coils 34. The brakingmechanism thus automatically protects the apparatus in case ofinterruption of the motor-circuit while the platforms are elevated andloaded.

While the form of my invention hereinbefore described and illustratedhas been found to give excellent results, it will be understood by thoseskilled in the art that changes may be made without departing from thespirit of my invention.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. In combination, a mainv working floor having a pit formed in it, apair of verticallymovable platforms or tables located one at each end ofsaid pit, a runway in said pit, means beneath the floor-level for movingsaid platforms from the main floor-level to the level of the runway andvice versa, rails carried by each platform, rails in alinement therewithcarried by the main platform and connecting the adjacent ends of therails of the different movable platforms when the latter are in theirfloor-level position.

2. In combination, a working floor having a pit formed in it, a pair ofvertically-movable platforms located in said pit and spaced apart fromeach other; means for moving said platforms from the floor-level to asublevel beneath the floor-level, a runway between the platforms at thesame level therewith when the latter are in their sublevel position, apair of parallel rails carried by each platform, the rails on eachplatform being in alinement with the corresponding rails of the otherplatform, rails carried at the floor-level connecting with the adjacentends of the rails of the two platforms when the latter are at thefloorlevel and other rails at the floor-level connecting with theopposite ends of the rails carried by the platforms when the latter areat the vfloor-level.

3. In combination, a working floor having a pit in it and a runway atthe bottom of the pit, a pair of movable platforms or tables located insaid pit and spaced apart from each other, and means for simultaneouslymoving said platforms from the level of said working floor to the levelof the runway and back, said means including a single prime mover foroperating both tables.

4. In combination, a working floor having a pit in it and a runway atthe bottom of the i pit, a pair of movable platforms or tables locatedin said pit and spaced apart from each other, means for moving saidplatforms from the level of said Working floor to the level of therunway and back, said means including l an electric motor for operatingboth tables, a brake normally holding said motor stationary, and anelectromagnetic device for releasing said brake.

- 5. In combination, a working floor having a pit in it and a runway atthe bottom of the pit, a pair of movable platforms or tables located insaid pit and spaced apart from each other and means for moving saidplatforms from the level of said working lioor to the level of therunway, said means including an electric motor for operating bothtables, a brake normally holding said motor stationary and anelectromagnetic device for releasing said brake, said device including awinding in series with the motor.

6. In combination, a main working floor having a pit formed in it, apair of movable platforms located in said pit and spaced apart from eachother, a pair of abutments spaced apart from each other, located in saidpit, and extending between the platforms, means for moving the platformsfrom the main floorlevel to the level of the abutments and back,including a shaft passing between said abutments.

WILLIAM ELMER, JR.

Witnesses:

A. G. SHARRA, W. E. RABOLD.

